The super-compact dimensions of the 1238DF allow it to partner with an accompanying subwoofer to deliver main monitor performance in rooms where space is at a real premium.
1238DF SAM™ Studio Monitor

Active Crossovers

Directivity Control Waveguide (DCW™) Technology

SPL
117 dB

Frequency Response
50 Hz - 20 kHz (-6dB)

Dimensions
H 610 x W 470 x D 257 mm, (view in inches)

Neutral and uncoloured
Ideal for music recording, post-production, broadcast and mastering, the 1238DF is the perfect blend of adaptable amplification, contemporary technology and classic design. With its controlled directivity, it offers all the neutrality and uncoloured performance of a large format Genelec monitor - but with a remote rack-mounting RAM-L amplification module that enables its amazingly modest and slimline cabinet size.

Configure, calibrate and control
The 1238DF is designed to partner with a complementary Genelec smart subwoofer, and integrates closely with our GLM software via which the whole system can be configured and calibrated for your listening environment, compensating for detrimental room influences to create a truly optimised monitoring solution. From simple stereo to complex immersive formats, the 1238DF and GLM combine seamlessly to help you produce mixes with exceptional translation to other rooms and systems.
Genelec
1238DF SAM™ Studio Monitor
1 x 1238DF monitor
1 x individually calibrated RAM-L amplifier
unit
1 x mains cable 1,8 m
1 x RJ45 cable 5 m (16 ft 4 in)
1 x RJ45 cable 10 m (32 ft 9 in)
1 x 10 m (32 ft 9 in) 4-pole Speakon
cables
1 x user manual
1238DF SAM™ Studio Monitor
Awards
Technical Specifications

SPL
117 dB

Amplifier Power
500 W Bass (Class D) + 250 W Midrange (Class D) + 200 W Treble (Class AB)

Frequency Response
50 Hz - 20 kHz ("-6 dB")

Accuracy of Frequency Response
± 2 dB (57 Hz - 20 kHz)

Driver Dimensions
2 x ⌀ 210 mm Bass + ⌀ 125 mm Midrange + ⌀ 25 mm Treble (view in inches)

Dimensions
H 610 x W 470 x D 257 mm, (view in inches)

Weight
36 kg / 79.4 lb

Connections
1 x XLR Analog Input
1 x XLR AES/EBU Input
1 x XLR AES/EBU Output
2 x RJ45 Control
1238DF SAM™ Studio Monitor
Technical Specifications
System Specifications
Frequency Response
57 Hz - 20 kHz (± 2 dB)
Low cutoff -6dB
50 Hz
High cutoff -6dB
20 kHz

SPL
Peak SPL Maximum peak acoustic output per pair in a listening room with music material at 2 m.
≥124 dB
Short term max SPL Maximum short term sine wave acoustic output on axis in half space, averaged from 100 Hz to 3 kHz at 1 m
≥117 dB
Long term max SPL Maximum long term RMS acoustic output in the same conditions with IEC weighted noise
≥107 dB
(limited by driver protection circuit) at 1 m.
Self-generated noise
Self-generated noise Self generated noise level in free space at 1 m on axis (A-weighted).
≤10 dB
Weight
Weight36 kg (79.4 lb)
Dimensions
Height
610 mm
Width
470 mm
Depth
257 mm

Enclosure
Enclosure material
MDF
Enclosure type
Sealed box
Drivers
Driver type
Cone
2 x 210 mm (8 in) cone
Count
2
Diameter
210 mm
Driver type
Cone
125 mm (5 in) cone
Diameter
125 mm
Driver type
Metal dome
25mm (1 in) metal dome
Diameter
25 mm
Directivity

Harmonic distortion
> 200 Hz ≤0.5 %
Amplifier Section
Amplifiers
500 W Class D
3U rack mounted amplifier (RAM-L)
Height
132 mm
Width
483 mm
Depth
240 mm
Weight
6 kg
(13.2 lb)
250 W Class D
200 W Class AB
Mains voltage
100-240 VAC 50/60Hz
Power consumption
ISS Active
≤0.5 W
Idle
≤25 W
Full output
750 W
Signal processing section
Connectors
Input Analog signal input connector XLR female, balanced 10 kOhm.
Input Digital signal input connector XLR female 110 Ohm.
Output Digital signal output / Thru connector XLR male 110 Ohm.
2 x Control Two CAT5 (RJ45) GLM Network connectors for computer control using the Genelec Loudspeaker Manager (GLM) software.
Crossover
Bass/Mid
420 Hz
Mid/Treble
3000 Hz
For even more technical details please see product operating manual.
Key Technologies

Active Crossovers

Directivity Control Waveguide (DCW™) Technology

Intelligent Signal Sensing (ISS™) Technology

Optimized Amplifiers

Protection Circuitry

Smart Active Monitor (SAM™) Systems
Active crossover operating at low signal levels.
Audio electronic crossovers allow to split the audio signal into separate frequency bands that can be separately routed to individual power amplifiers which then are connected to specific transducers optimized for a particular frequency band.
Active crossovers come in both digital and analogue varieties. Genelec digital active crossovers include additional signal processing, such as driver protection, delay, and equalization.
Genelec analogue active crossover filters contain electronic components that are operated at low signal levels suitable for power amplifier inputs. This is in contrast to passive crossovers that operate at the high signal levels of the power amplifier's outputs, having to handle high currents and in some cases high voltages.
In a typical 2-way system the active crossover needs two power amplifiers — one for the woofer and one for the tweeter.
The active crossover design offers multiple benefits:
- The frequency response becomes independent of any dynamic changes in the driver's electrical characteristics or the drive level.
- There is an increased flexibility and precision to adjust and fine tune each output frequency response for the specific drivers used.
- Each driver has its own signal processing and power amplifier. This isolates each driver from the drive signals handled by the other drivers, reducing inter-modulation distortion and overdriving problems.
- The ability to compensate for sensitivity variations between drivers.
- The possibility to compensate for the frequency and phase response anomalies associated with a driver’s characteristics within the intended pass-band.
- The flat frequency response of a high-quality active loudspeaker is a result of the combined effect of the crossover filter response, power amplifier responses and driver responses in a loudspeaker enclosure.
Using the active approach enables frequency response adjustments and optimization of the full loudspeaker system, placed in various room environments, without expensive external equalizers. The end result is a simpler, more reliable, efficient, consistent and precise active loudspeaker system.
Directivity Control Waveguide (DCW™) for flat on- and off-axis response.
A revolutionary approach was taken by Genelec in 1983 with the development of its Directivity Control Waveguide (DCW™) used at the time in an egg-shaped enclosure. The Genelec DCW technology developed and refined over more than 30 years greatly improves the performance of direct radiating multi-way monitors.
The DCW technology shapes the emitted wavefront in a controlled way, allowing predictable tailoring of the directivity (dispersion) pattern. To make the directivity uniform and smooth, the goal is to limit the radiation angle so that the stray radiation is reduced. It results in excellent flatness of the overall frequency response as well as uniform power response. This advanced DCW technology minimizes early reflections and provides a wide and controlled listening area achieving accurate sound reproduction on- and off-axis.
Minimized early reflections and controlled, constant directivity have another important advantage: the frequency balance of the room reverberation field is essentially the same as the direct field from the monitors. As a consequence, the monitoring system's performance is less dependent on room acoustic characteristics.
Sound image width and depth, critical components in any listening environment, are important not only for on-axis listening, but also off-axis. This accommodates not only the engineer doing his or her job, but also others in the listening field, as is so often the case in large control rooms.
DCW™ Technology key benefits:
- Flat on- and off-axis response for wider usable listening area
- Increased direct-to-reflected sound ratio for reduced control room coloration
- Improved stereo and sound stage imaging
- Increased drive unit sensitivity up to 6 dB
- Increased system maximum sound pressure level capacity
- Decreased drive unit distortion
- Reduced cabinet edge diffraction
- Reduced complete system distortion
Intelligent Signal Sensing (ISS™) for power consumption reduction in stand-by mode.
Introduced early 2013, Genelec’s Intelligent Signal-Sensing technology has been developed to meet with both European Union ErP Directives and the company’s own wider sustainability commitments.
The Intelligent Signal Sensing, ISS™ circuitry tracks the signal input of the loudspeaker and detects if it is in use. If the ISS circuit does not find any audio on the input for a period of time, it sets the loudspeaker to a low-power sleep state and the loudspeaker will consume less than 0.5 watts. When an input signal is detected, the loudspeaker immediately turns itself on. Basically, the loudspeaker system will start saving power as soon as work is interrupted.
Additionally an ‘ISS Disable’ switch is located on each product’s back plate next to the other room response controls. First, when the mains power switch of the loudspeaker is set to “ON”, the ISS™ auto-start function (low-power sleep state on/off) of the loudspeaker is active.
If this function is not desired, the ISS™ function can be disabled by setting the “ISS Disable” switch on the back panel to “ON” position. In this mode, the monitor is only powered on and off using the mains power switch.
Note that the mains power switch will always turn the monitor off completely.
Each transducer is driven by its own optimized amplifier.
Audio electronic crossovers allow to split the audio signal into separate frequency bands that can be separately routed to individual power amplifiers which then are connected to specific transducers optimized for a particular frequency band.
In a typical 2-way loudspeaker system, the active crossover needs two power amplifiers — one for the woofer and one for the tweeter. The power amplifiers are connected directly to the drivers of an active loudspeaker, resulting in the power amplifier’s load becoming much simpler and well known. Each driver-specific power amplifier has only a limited frequency range to amplify (the power amplifier is placed after the active crossover) and this adds to the ease of design.
The active design principle offers multiple benefits:
- The power amplifiers are directly connected to the speaker drivers, maximizing the control exerted by the power amplifier’s damping on the driver’s voice coil, reducing the consequences of dynamic changes in the driver electrical characteristics. This may improve the transient response of the system.
- There is a reduction in the power amplifier output requirement. With no energy lost in the passive crossover filter components, the amplifier power output requirements are reduced considerably (by up to 1/2 in some cases) without any reduction in the acoustic power output of the loudspeaker system. This can reduce costs and increase audio quality and system reliability.
- No loss between amplifier and driver units results in maximum acoustic efficiency
- Active technology can achieve superior sound output vs. size vs. low frequency cut-off performance
- All loudspeakers are delivered as a factory aligned system (amplifiers, crossover electronics and enclosure-driver systems)
Sophisticated drive unit protection circuitry for safe operation.
When working in critical audio production environments it is essential that monitoring systems remain reliable and functional at all times. One of the main reasons behind Genelec’s excellent success in broadcasting environments is the reliability of our products and a key element behind the reliability is the internal protection circuitry found in all products since 1978.
The protection circuitry prevents driver failures by detecting signal levels, and in case of sudden peaks or constantly too high levels, taking the signal level down automatically. Of course this feature does not affect the sound quality in any way when working within the specifications of the loudspeaker, but only prevents inadequate input signals from breaking the loudspeaker.
Protection circuitry features and benefits:
- Reduces the output level when required, (e.g. when driver voice coil temperature reaches the safe limit) which highly improves the system reliability
- Appropriate protection circuitry design in every loudspeaker and subwoofer enables to maximise system output sound level.
Networked Smart Active Monitor (SAM™) Systems feature automatic calibration to the environment.
The last decade has experienced a rapid increase in global media content creation, resulting in significant changes in the way network facilities deal with increased workload. Now, more than ever, a growing number of audio productions are done in tighter, more confined working environments. This increases acoustic problems and lowers the reliability of monitoring. At the same time, a professional audio engineer needs to have high confidence in a reliable and precise monitoring system that reproduces sound neutrally and without distortion.
Built upon the solid electro-acoustic foundations of the 1200, 8000 and 7000 Series products, Genelec advanced SAM Systems are today’s most advanced and flexible monitoring solutions. They are an indispensable tool for audio professionals, as they are capable to automatically adapt to the acoustic environments and correct for levels, delays and room anomalies. SAM Systems can be controlled via Genelec proprietary Loudspeaker Manager (GLM™) network and software, enabling you to build a highly flexible and reliable monitoring system.
The GLM 3 software is a highly intuitive and powerful monitor control networking system that manages connectivity to all SAM studio monitors and subwoofers on the network – up to 30. The GLM 3 software features adjustment of levels, distance delays and flexible room response compensation equalization with the state-of-the-art and robust AutoCal™ automated calibration system. All parameters and settings are stored in system setup files or saved in each individual monitor or subwoofer if the GLM network needs to be disconnected.
Also, all acoustical features of SAM Systems can be optimised for different working styles or client demands. Additionally, even if the monitors or the production projects move between rooms, you can expect SAM technology to achieve the highest consistency in monitoring, providing a neutral sound stage imaging with low distortion.
Genelec SAM Systems offers a comprehensive, solution-oriented, intelligently networked product range supporting analogue and digital signals in virtually any working environment.
References

The highlight of TCM’s Genelec monitoring solutions can be found in the flagship recording studio. “The studio is used mainly by students who major in the Fine Art/Film Scoring course within the composition program,” explains TCM lecturer Hideaki Sano. “The course focuses on composition, arrangement and performance, but also studies practical techniques related to pre-production, studio recording, producing, and so on. The studio needed to be capable of recording an entire orchestra, and since we have a concert hall and other large performance spaces on campus, we wanted the studio to make efficient use of these facilities.”
Mr. Hideaki Sano of Tokyo College of Music
With this brief in mind it was clear that the studio would need to be the centrepiece of the new campus. To ensure the best possible results, TCM turned to world-renowned acoustician, Masami “Sam” Toyoshima, to handle the studio’s acoustic design. Meanwhile, the equally important task of studio planning and operation was given to Mixer’s Lab, thanks to its history and track record running its own studios as well as offering engineering and consultancy services.
The technology in the studio is clearly high-end, matching the standards that TCM demands. Nowhere is this clearer than with the studio monitoring. The solution comprises Genelec 1234A, 1238AC and 1238DF smart active main monitors in a 5.1.2 immersive configuration, with 8351A coaxial monitors for stereo nearfield monitoring. For Hideo Takada of Mixer’s Lab, the decision to go with Genelec monitors was an easy one: “I've been using Genelec reference monitors at work for a long time, so I know their sound inside out. They work well with acoustic instruments, pop music, and a wide variety of genres. It’s a studio monitor you can trust.”
Mr. Hideo Takada of Mixer's Lab
If the choice of brand was an easy decision, the configuration of the space was a different matter entirely. “The college originally requested the studio to be at least a 2-channel environment, and be able to conduct high-quality recording,” recalls Takada. “But as the studio planning developed, we considered that it should support surround. I had just experienced Dolby Atmos mixing myself, and realised the importance of it, so we opted for 1234As as L/R, a 1238AC for the centre channel, two 1238DFs for surrounds and two more 1238DFs as height speakers – due to the compact nature of the studio.”
For stereo nearfield work, TCM opted for 8351A three-way point source monitors from The Ones series. “What’s great about coaxial monitors is that you get one coherent sound,” explains Mixer’s Lab’s Tatsuo Umezu. “A certain sound can be perceived from one point as if it's a matter of course, and the centre of the sound doesn't get ‘blurred’. I can tell exactly where the mic was placed, and how far it was from the instrument. I suppose this is exactly what Genelec aimed for.”
A monitor needs to be comfortable to listen to, and Genelec has that quality.
Reflecting on the qualities the Genelec monitoring solutions have brought TCM, Sano is clearly very happy with their performance: “Genelec monitors have the same sound even when the playback volume is low, and that's one of the benefits. And the fact that it has become the industry standard is the key to our choice. Experiencing that industry standard sound is extremely beneficial for our students before they start to work as professionals.
“It's about the balance of the richness and the accuracy of the sound,” he continues. “A monitor needs to be comfortable to listen to, and Genelec has that quality – plus the accuracy to comprehend every detail of the sound whatever the genre. Genelec can precisely playback an orchestra, a violin solo, pop music, EDM, and much more. It’s a monitor we can completely count on.”
How GLM™ (Genelec Loudspeaker Manager) Software Works
How GLM™ (Genelec Loudspeaker Manager) Software Works
Frustrated that your material doesn’t sound so great on other systems? In this video we show you how to calibrate the Genelec SAM™ monitors with the Genelec Loudspeaker Manager (GLM™) Software to get the most out of your room and ensuring that your mixes translate perfectly.